There are a multitude of known fire extinguishing agents, and methods and systems for using the same. The mechanism by which these fire extinguishing agents extinguish a fire can vary from agent to agent. For instance, some fire extinguishing agents operate by inerting or diluting mechanisms that act to deprive the fire of necessary chemicals, such as oxygen or fuels. Other fire extinguishing agents operate chemically to extinguish a fire. Such chemical actions may include scavenging free radicals, thereby breaking the reaction chain required for combustion. Still, other fire extinguishing agents operate thermally to cool the fire.
Traditionally, certain bromine-containing compounds such as Halon 1301 (CF3Br), Halon 1211 (CF2BrCl), and Halon 2402 (BrCF2CF2Br) have been used as fire extinguishing agents for the protection of occupied rooms. Although these Halons are effective fire extinguishing agents, some believe that they are harmful to the earth's protective ozone layer. As a result, the production and sale of these agents has been prohibited.
Relatively recently, fluorocarbons such as hydrofluorocarbons, fluoroethers and fluorinated ketones have also been proposed as effective fire extinguishing agents. Fluorocarbon systems may be relatively inefficient and can be high in cost. In addition, some fluorocarbon fire extinguishing agents may react in the flame to form various amounts of decomposition products, such as HF. In sufficient quantities, HF is corrosive to certain equipment and poses a significant health threat.
In addition to fluorocarbon agents, inert gases have been proposed as replacements for the Halon fire extinguishing agents. Gases such as nitrogen or argon, and also blends, such as a 50:50 blend of argon and nitrogen have been proposed. These agents can be very inefficient at fire extinguishing, and as a result, significant amounts of the gas are necessary to provide extinguishment. The large amounts of gases required for extinguishment results in the need for a large number of storage cylinders to store the agent, and ultimately, large storage rooms to house the gas storage cylinders.
Hybrids of fluorocarbons and gas blends have also been proposed as fire extinguishing agents. For example, U.S. Pat. No. 6,346,203 to Robin et al. proposes delivering to the fire gas and fluorocarbon fire extinguishing agents.
Finally, water mists have also been used for the suppression of compartment fires. Hybrid fire extinguishing systems utilizing a water mist followed by the application of either fluorocarbon or gas agents have been proposed.
It would desirable to develop improved fire extinguishing agents and systems.